.TH std::experimental::optional::swap 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::experimental::optional::swap \- std::experimental::optional::swap

.SH Synopsis
   void swap( optional& other ) noexcept(/* see below */);  (library fundamentals TS)

   Swaps the contents with those of other.

     * If neither *this nor other contain a value, the function has no effect.
     * If only one of *this and other contains a value (let's call this object in and
       the other un), the contained value of un is direct-initialized from
       std::move(*in), followed by destruction of the contained value of in as if by
       in.val->T::~T(). After this call, in does not contain a value un contains a
       value.
     * If both *this and other contain values, the contained values are exchanged by
       calling using std::swap; swap(**this, *other). T lvalues must satisfy Swappable.

.SH Parameters

   other - the optional object to exchange the contents with

.SH Return value

   \fI(none)\fP

.SH Exceptions

   noexcept specification:
   noexcept(std::is_nothrow_move_constructible<T>::value &&
              noexcept(swap(std::declval<T&>(), std::declval<T&>())))

   In the case of thrown exception, the states of the contained values of *this and
   other are determined by the exception safety guarantees of swap of type T or T's
   move constructor, whichever is called. For both *this and other, if the object
   contained a value, it is left containing a value, and the other way round.

.SH See also

   std::swap(std::experimental::optional) specializes the std::swap algorithm
                                          \fI(function)\fP

.SH Categories:
     * Noindexed pages
     * conditionally noexcept
